An algorithm for 3D reconstruction of deformable shape sequences

In this paper, we present an algorithm for estimating the 3D model of a deformable shape from a video sequence. Our method assumes that a deformable shape sequence can be represented by a linear combination of basis shapes, where the weights assigned to each basis shape change with time. While there is existing work on estimating the basis shapes and their combination coefficients, they lack the crucial information about the number of basis shapes that are required for the model. This is usually determined through heuristics about the physics of the underlying structure. We show that it is possible to estimate the number of basis shapes from the tracked points obtained from the video sequence, using a scaled orthographic camera projection model. This estimate is then used to compute the 3D structure of each of the basis shapes. We present experimental results in recreating the structure of the human body during various activities from a video sequence.